When seeding a field or applying other inputs, a standard approach by producers is to make one to three headland passes around the field while applying seed and or fertilizer. Back and forth passes are then made in the center area of the field. By first planting in the headland passes, a line is formed in the field to indicate where to start and stop the back and forth passes in the center area while turning in the implement in the previously seeded headland area. A disadvantage of such a pattern is that while turning in the headland area, the tractor and implement will drive over the previously seeded headland area, causing compaction of the soil and disturbing the already planted seed. One way to avoid compaction of previous seeded soil is to seed the headline area last. This approach, however, requires the operator to estimate the point in the field where the back and forth passes start and stop. To ensure that the field is completely seeded, operators will tend to overlap into the inner headland area. When the headland area is subsequently planted, there will be an area that is double seeded and/or which may have double the amount of fertilizer or other chemical applied thereto.
Recent advances in machine technology have enabled individual product dispensors of a planter to be selectively turned off to avoid dispensing seed where seed has already been planted or where it is desired not to plant seed. One technology for doing so is shown in U.S. Pat. No. 7,571,688, hereby incorporated by reference, where clutches are provided between the drive cable and seed meter to enable the each seed meter to be separately turned off. Another example is shown in U.S. patent application Ser. No. 12/481,254, filed Jun. 9, 2009, and also incorporated herein by reference, in the context of an air seeder where a section of dispensers can be selectively turned off by closing the outlet from the meter. Such technology is a beneficial when finishing the last back and forth pass where the width of the implement is wider than the remaining area to be seeded resulting in a portion of the implement overlapping previously seeded soil in the headland area. The dispensers in the headland area can be turned off to avoid double seeding. However, the ground engaging tools of each dispenser still engage soil and can disturb the previously planted seed. Furthermore, the tires of the implement and tractor can cause soil compaction around the planted seed.
The individual row clutches or the section control can also be beneficial in planting an irregularly shaped field where all of the rows do not end at the same point where the implement passes into the headland area. As the implement approaches the end of the rows, individual row units or sections of row units can be shut off individually to avoid the double planting in the headland.
Similar technology is available for use on sprayers to individually shut off the spray nozzles to avoid double spraying.